KR100949598B1 - High-strength Polyester fiber for industry and its manufacturing method - Google Patents

Abstract

The present invention relates to a high-strength low-shrink polyester fiber and a method for producing the same, characterized in that the strength is 7.3g / d or more, cutting elongation 20 to 28%, shrinkage of 2.5% or less. In addition, thermal stress peak values of 6.0 × 10 ^-2 to 10 × 10 ^-2 g / d and 14.0 × 10 ^-2 to 20.0 × 10 ^-2 g / d in the temperature range of 120 to 180 ° C and 220 to 280 ° C, respectively, It is characterized by. The low shrinkage polyester fiber according to the present invention not only has sufficient resistance to external loads, but also has no shrinkage unevenness during post-processing for the manufacture of industrial products such as tarpaulins, truck covers, signboards, tent papers, etc. Very useful as an industrial textile material.

Low shrinkage, polyester, thermal stress, industrial

Description

High-strength polyester fiber for industry and its manufacturing method

The present invention relates to a high-strength low-shrink polyester fiber and a method of manufacturing the same, and in particular, not only has sufficient resistance to external loads, but also has no shrinkage unevenness during post-processing and is excellent in form stability. It relates to a high-strength low-shrink polyester fiber that can be usefully used as industrial textile materials such as paper, tents and the like and a method of manufacturing the same.

  Polyester fibers are excellent in physical and chemical properties, and their use continues to expand as industrial fibers. In particular, high strength polyester fibers are used as the base fabric of industrial coated fabrics such as tarpaulins, truck covers, signboards, tents and the like. However, tarpaulins, truck covers, signboards, tents, etc., are coated with PVC resin on the base fabric at a temperature of 150 to 230 ° C. In this process, high strength polyester fibers, which are typical of shrinkage characteristics, have poor shrinkage characteristics, resulting in uneven shrinkage. Occurs and affects the shape stability, there is a disadvantage that the quality of the coated fabric by the deformation of the fabric form. Therefore, polyester fibers having high strength properties and low shrinkage properties are demanded from the user's point of view and are actively being researched in related manufacturing industries.

A method for producing low-shrink polyester fibers, transverse stretching in which undrawn yarn (UDY, Undrawn Yarn) or partially stretched yarn (POY) is stretched, heat treated and relaxed in a separate facility after spinning. There is a warp drawing process. In Korean Patent Publication No. 195-0000717, an undrawn or partially drawn yarn is drawn and heat treated by a separate transverse drawing device to obtain a strength of 8.0g / d or more, a dry heat shrinkage ratio of less than 2% (190 ° C), and a stretch of 15 to 25%. Such a transverse stretching process for producing ester fibers is disclosed. However, since the lateral stretching process requires a separate stretching facility, there are problems in economic aspects, such as an increase in facility investment cost, a decrease in productivity, and an increase in manufacturing cost.

As another method for producing low shrinkage polyester fibers, Japanese Patent Application Laid-Open No. 46-6459 discloses a direct spinning drawing process in which spinning, stretching and relaxation processes are performed in one continuous step. According to the direct radiation drawing method, Korean Patent No. 0193940 proposes a method for producing a high elongation low shrinkage polyester fiber having a single fineness of 7 to 15 deniers with a total draw ratio of 5.0 to 6.5 and a relaxation rate of 10 to 15%. However, this method showed a high dry heat shrinkage of 3.3% even at the high relaxation rate of 12.7%, although the spinning speed was reduced to 600m / min to increase the residence time on the high-pressure roller.

  As described above, in the case of producing low shrinkage polyester fiber by direct radiation drawing method, increasing the total draw ratio to obtain high strength fiber increases the orientation of the amorphous region in the fiber, thereby increasing the shrinkage rate and relaxing to reduce the shrinkage rate. Increasing the rate increases the vibration of the yarn on the high-speed roller, which causes a problem in that process workability such as trimming occurs is lowered.

In addition, US Pat. A separate heating plate must be installed.

On the other hand, Korean Patent Laid-Open Publication No. 1998-028329 discloses a method for manufacturing a low shrinkage yarn by additionally installing a heating and cooling device and a steam supply device between the rollers. However, in order to apply this method to the actual production process, a lot of installation space is required, and it is not economical due to a lot of equipment investment such as adding a heating device, a cooling device, and a steam supply device.

The technical problem to be achieved by the present invention is not only to have sufficient resistance to external load in order to solve the above problems, there is no shrinkage non-uniformity during post-processing and excellent form stability, such as tarpaulin, truck cover, signboard, tent, etc. It is to provide a high-strength low-shrink polyester fiber and a method for producing the same that can be very useful as industrial fibers.

The invention The technical problem strength 7.3 ~ 8.5g / d or higher, elongation cut 18-28% in order to achieve, and shrinkage of 2.5% or less, respectively, 6.0 ㅧ in a temperature range of 120 ~ 180 ℃ and 220 ~ 280 ℃ 10 ^{- It} provides a high strength low shrinkage polyester fiber characterized in that the thermal stress peak value of ² ~ 10 × 10 ^-2 g / d and 14.0 × 10 ^-2 ~ 20.0 × 10 ^-2 g / d appear.

  In the high strength low shrinkage polyester fiber according to the present invention, the [thermal stress peak value in the temperature range of 220 to 280 ° C.] / [Thermal stress peak value in the temperature range of 120 to 180 ° C.] is 1.5 to 3.5. desirable.

  The present invention is a method for producing a polyester fiber by direct radiation stretching to achieve the above technical problem, (a) spinning a molten polyester polymer at a speed of 400 ~ 800m / min; (b) drawing the spun polyester fibers at a total draw ratio of 4.5 to 7.5; It provides a high-strength low-shrink polyester fiber manufacturing method comprising a; and (c) relaxing the stretched polyester fiber by heat treatment of a high roller at 7.0 to 15.0% relaxation rate.

  In the high-strength low-shrink polyester fiber manufacturing method according to the present invention, the relaxation step of step (c) is carried out divided into primary and secondary relaxation process, the primary relaxation process: the relaxation rate by the secondary relaxation process is 9 It is preferable to distribute from 1: 1 to 1: 9.

Hereinafter, the high strength low shrinkage polyester fiber and the manufacturing method thereof according to the present invention will be described in detail.

  The high strength low shrinkage polyester fiber according to the present invention can be produced by the following direct radiation drawing method. First, the polyester polymer is melted and discharged through a spinning nozzle at a speed of 400 to 800 m / min. The intrinsic viscosity (I.V.) of the polyester polymer to be used is preferably 0.75 to 1.10 in consideration of the high strength and low shrinkage characteristics, spinning workability and the like of the finished fiber. The intrinsic viscosity of the polymer is determined by the use of a 6: 4 mixture of phenol / 1,1,2,2-tetrachloroethane to produce a 0.4% polyester / solvent solution, which is a pure solvent that passes through standard capillaries with Canon's Auto Visc II automatic viscometer. The flow time of the polyester / solvent solution with respect to the flow time was measured and then calculated by the following Bilmeyer approximation. Where C is the concentration (g / 100ml).

Thereafter, the spun polyester undrawn yarn is drawn to a total draw ratio of 4.5 to 7.5. If the draw ratio is less than 4.5, it is difficult to obtain high strength fibers because the degree of fiber orientation is low. If the draw ratio exceeds 7.5, the process workability such as trimming occurs is deteriorated, and pin yarn and wool are generated, thereby deteriorating the appearance quality of the final product. The stretched polyester fiber is then relaxed at a relaxation rate of 7% to 15%. In the relaxation process, the heat treatment of the fiber does not require any additional equipment such as a heating plate or a steam supply device. If the relaxation rate is less than 7%, it is difficult to achieve low shrinkage characteristics, and if the relaxation rate is more than 15%, there is severe vibration on the high-pressure roller, and stable process workability is not secured. The relaxation process may be carried out in a single process, but it is preferable to divide the process into primary and secondary relaxation processes. At this time, the primary relaxation process: the relaxation rate by the secondary relaxation process is 9: 1 to 1: 9. It is preferable to distribute. As described above, when the two-stage relaxation process is used, not only the vibration of the yarn on the high-pressure roller is reduced, but also the retention time of the fiber is sufficient, so that the heat treatment efficiency is increased, so that the real relaxation rate and the application relaxation rate are close to each other. This is better expressed. Fibers thus processed may be wound at a speed of 2000 m / min or more to obtain polyester fibers having excellent high strength and low shrinkage properties.

The method for producing a high strength low shrinkage polyester fiber according to the present invention described above is advantageous in terms of economics by applying heat from the roller itself, and thus does not require a separate cooling device and a heating device, such as spinning speed, total draw ratio, and relaxation rate. By appropriately adjusting the process operating conditions, industrial polyester fibers having excellent properties of strength of 7.3 g / d or more, elongation at break of 18 to 28%, and shrinkage of 2.5% or less can be prepared.

The high strength low shrink polyester fibers made in accordance with the present invention exhibit the following characteristic thermal behavior. Two thermal stresses, 6.0 × 10 ^-2 to 10 × 10 ^-2 g / d and 14.0 × 10 ^-2 to 20.0 × 10 ^-2 g / d, respectively, in the temperature range of 120 to 180 ° C and 220 to 280 ° C. The peak value is shown. The high-strength low-shrinkage polyester fiber produced by the conventional direct spinning and transverse stretching process has a low peak value in the low temperature region even if only one peak appears or two peaks. It has a different thermal behavior than fiber. 1 is a graph showing the thermal stress behavior of high-strength low-shrink polyester fibers according to Example 1 of the present invention and the prior art.

As shown in FIG. 1, a difference in thermal stress peaks of Comparative Example 1 obtained according to the related art compared to Example 1 appears. Although the peak in the high temperature region is clearly visible in both Example 1 and Comparative Example 1, it can be seen that the comparative example 1 is weaker than the peak in the low temperature region Example 1.

The high strength low shrinkage polyester fiber according to the present invention exhibits excellent properties of strength of at least 7.3 g / d, elongation at break of 18 to 28%, and shrinkage of at most 2.5%, and thus not only has sufficient resistance to external load, but also shrinkage at post processing. There is no uneven phenomenon and excellent shape stability. Therefore, it can be very usefully used as an industrial fiber, such as tarpaulin, truck cover, signboard, tent.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples and comparative examples are for illustrative purposes only and should not be understood as limiting the scope of the invention.

<Example 1>

After melting a polyester solid-state polymerized chip having an intrinsic viscosity of 0.84 and spinning and cooling it at a speed of 480 m / min through a spinneret, the first roller GR1 and the fourth roller ( Stretching was carried out between GR4). At this time, the speed of the fourth roller GR4 was adjusted to 2800 m / min so that the total draw ratio was adjusted to 5.7. The temperature of the 4th roller GR4 and the 5th roller GR5 was 240 degreeC, and the 1st and 2nd heat setting were performed, and the 1st relaxation rate 7% in the 4th roller GR4 and 5th roller GR5. The secondary relaxation rate was adjusted to 3% between the fifth roller GR5 and the sixth roller GR6 so that the total relaxation rate was 10%. Thus, the fiber which passed two-stage relaxation process was wound up by the winding machine, and the polyester fiber of 1000 denier of fineness was obtained.

<Examples 2-3, Comparative Examples 1-2>

The same process as in Example 1 was conducted except that the total draw ratio and the temperature, relaxation rate, and relaxation rate distribution ratio of GR4 and GR5 were changed as shown in Table 1.

The physical properties of the polyester fibers prepared according to the Examples and Comparative Examples were measured and shown in Table 1 below.

Yarn strength and elongation at break were measured at a sample length of 250 mm, 80 TPM flammability, and 300 mm / min tensile rate, based on ASTM D885. The strength of the measured yarn divided by the weight of the yarn 9,000 m was determined as the strength of the yarn.

  The shrinkage percentage (%) measured the difference in length after standing at 190 ° C. for 15 minutes while applying 0.01 g / d load to the sample in the test light.

  Thermal stress is applied by Kanebo Thermal Stress Tester (Type KE-3LS) to apply a superload of 0.05g / d and fix it in a loop shape with knots attached to the upper and lower hooks, and then heat it from room temperature to 300 ℃ at a heating rate of 150 ℃ / min. The stress behavior was measured continuously.

TABLE 1

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Total draw ratio 5.7 6.0 6.2 5.7 6.0 GR 4/5 temperature (℃) 240/240 250/250 250/250 240/190 250/190 % Relaxation 10 12 12 8 11 Allocation ratio 7: 3 9: 1 9: 1 10: 0 10: 0 Strength (g / d) 7.53 7.82 8.03 7.87 8.07 Body cut (%) 22.5 24.3 24.1 24.6 25.4 Shrinkage (%) 1.4 1.7 2.0 3.0 3.2 Thermal Stress Peak Temperature (℃) 155/262 158/260 152/260 163/260 161/262 Thermal Stress (× 10 ^-2 g / d) 8.1 / 16.8 8.3 / 16.5 8.9 / 17.2 5.2 / 18.4 5.3 / 18.7

The draw ratio, relaxation rate and distribution ratio used in Table 1 are defined as follows, respectively.

1) elongation ratio = rotation speed of GR4 / rotation speed of GR1

2) Relaxation rate (%) = primary relaxation rate (%) + secondary relaxation rate (%)

3) 1st relaxation rate (%) = (GR4 rotation speed-GR5 rotation speed) / GR4 rotation speed × 100

4) 2nd Relaxation Rate (%) = (GR5 Speed-GR6 Speed) / GR5 Speed × 100

5) Allocation Ratio = 1st Relaxation Rate: 2nd Relaxation Rate

Referring to Table 1, in accordance with the present invention, 6.0 × 10 ⁻² to 10.0 × 10 ⁻² g / d and 14.0 × 10 ⁻² to 20.0 × 10 ⁻ , respectively, in the temperature range of 120 to 180 ° C. and 220 to 280 ° C. It can be seen that the polyester fibers (Examples 1 to 3) exhibiting a thermal stress peak value of ² g / d simultaneously have excellent strength and low shrinkage characteristics. On the other hand, the fibers of Comparative Examples 1 and 2 are excellent in strength but low in shrinkage characteristics, it can be expected that the morphological stability due to shrinkage in the post-process for the production of industrial products such as tarpaulin, signboards, tents, and the like.

Although the present invention has been described in detail only with respect to the specific examples and comparative examples described, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the present invention, and such variations and modifications are attached thereto. Naturally, it belongs to the claim.

1 is a graph showing the thermal stress behavior of high-strength low-shrink polyester fibers according to Example 1 and Comparative Example 1 of the present invention.

Claims (4)

Spinning the molten polyester polymer at a speed of 480m / min, and the drawn polyester fiber at a total draw ratio of 5.7 to 6.2 with a speed of the fourth roller at 2800m / min during the stretching step through the first to fourth roller As a polyester fiber prepared by stretching, The fiber has a strength of 7.3 to 8.5 g / d, an elongation at break of 18 to 28%, a shrinkage of 2.5% or less, and 6.0 × 10 ⁻² to 10.0 × 10 ⁻² g in the temperature range of 120 to 180 ° C. and 220 to 280 ° C., respectively. thermal stress peak values of / d and 14.0 × 10 ⁻² to 20.0 × 10 ⁻² g / d, and (High thermal stress peak value in the temperature range of 220-280 degreeC) / (The thermal stress peak value in the temperature range of 120-180 degreeC) is 1.5-3.5, The high strength low shrinkage polyester fiber characterized by the above-mentioned. delete delete delete

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